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Title: Gamma-ray burst polarization via Compton scattering process

Synchrotron radiation and Compton scattering are widely accepted as the most likely emission mechanisms of some astrophysical phenomena, such as gamma-ray bursts (GRBs) and active galactic nuclei. The measurement of the polarization of photons provides a useful tool to distinguish different emission mechanisms and structures of the emission region. Based on the differential cross section of a polarized photon scattered by an unpolarized electron of any initial momentum, we derive an analytical formula of polarization for beamed photons scattered by isotropic electrons with a power-law distribution. Numerical calculations are carried out in four special cases: electrons at rest, Thomson limit, head-on collision, and monochromatic electrons. It is found that the maximum polarization can be as high as 100% for low energy photons, if the electrons are at rest. Although polarization is highly suppressed due to the isotropic electrons, a maximum value of ∼10%-20% can still be achieved. The Compton scattering process can be used to explain the polarization of GRB 041219A and GRB 100826A.
Authors:
;  [1] ;  [2]
  1. Institute of High Energy Physics, Chinese Academy of Sciences, 100049 Beijing (China)
  2. School of Space Science and Physics, Shandong University at Weihai, 264209 Weihai (China)
Publication Date:
OSTI Identifier:
22351371
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal; Journal Volume: 783; Journal Issue: 1; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ASTROPHYSICS; BEAMS; COLLISIONS; COMPTON EFFECT; COSMIC GAMMA BURSTS; DIFFERENTIAL CROSS SECTIONS; DISTRIBUTION; ELECTRONS; EMISSION; GALAXY NUCLEI; MONOCHROMATIC RADIATION; PHOTONS; POLARIZATION; SYNCHROTRON RADIATION